Question

Experiment to find the enthalpy change for the reaction

Zn(s) + Cu²⁺(aq) → Cu(s) + Zn²⁺(aq)

2. Pipette 25 cm cubed of the copper sulphate solution into a polystyrene cup.

3. Weigh about 6 g of zinc powder in the weighing bottle. (since this is in excess

there is no need to be accurate).

4. Put the thermometer through the hole in the lid,stir and record the

temperature to the nearest 0.1 oC every half minute for 2.5 minutes.

5. At precisely three minutes,add the zinc powder to the cup.

6. Continue stirring and record the temperature for an additional 6 minutes to

complete the results table on the following page.

Calculate the Enthalpy change for ∆H for quantities used 

Calculate ∆H for 1 mol of zinc and CuSo₄(aq)

Compare your result with accepted value of -217kJmol^-1 by calculating the % error in your answer

Answer 1

Enthalpy change for quantities used ;

$=-210.53kJ/mol$

∆H for 1 mol of zinc and CuSo4(aq);

$=-241.82kJ/mol$

% error;

$=3.74\%$